No words

I am so pissed off by the immigration ban, and all the circumstances surrounding it.  I feel as if the most pessimistic predictions about a Trump presidency are coming to fruition, and the truly morbid ones sound realistic.  Are we currently witnessing the rise of the American Hitler?  The fall of the US?  Is this the prelude to WWIII, this time with nuclear weapons?  Does anything else matter?

When I set out to write a post, I usually start with a potentially contentious point, and build arguments in favor or against it.  But in this situation, there is no contentious thesis, and no one to argue with.  This is unacceptable, and I can’t think of what else to say about it.  I don’t think I could bear to turn it into yet another thesis and essay.  Blogging simply isn’t the right tool to address this problem.

I have a draft, entirely unwritten, where I talk about the value of low-priority activism.  For example, atheist activism is still valuable even though religion isn’t the root of all evil.  Feminism is still important even if not everything can be blamed on the patriarchy.  It’s okay to fight for a thing that is not the most important thing.  Anyway we don’t even know what the most important thing is.  You get the general idea.

I still stand by this thesis, but just this moment I’m not feeling it.  Because right now we do know what the most important thing is, and that is to stop Trump.

My issues with queer-positive atheism

Following my big rant on queer-positive Christianity, I have a much shorter rant on queer-positive atheism. There are fewer things to unpack, but even the smaller issues are important to me, because I interact more frequently with atheists than I do with religious people.

So you’re not a fundamentalist Christian

The number one criticism I have about atheist attitudes towards queer people is that they’re very self-satisfied about it. Yes, we all know you’re way ahead of fundamentalist Christians. We all know you were in favor of same-sex marriage (or opposed to all marriage) before it was cool. Good for you?

As I previously said, one of my major issues with queer-positive Christianity is that they’re starting from very low standards, the standards of Christianity. Atheists have the advantage of being able to scrap Christian standards entirely and build something better. But you’re tossing out your advantage if you’re always comparing your attitudes to those of very religious people.

And I’m not even saying that we as atheists need to be more ashamed of [insert prominent anti-SJ atheist here]. Shame is not what I’m going for at all. It’s just that, even when we’re all on the same page about social justice, social justice is still a thing that takes work and not just lip service.
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Announcements

Mandisa Thomas, president of Black Nonbelievers, is giving a talk this Sunday!  If you live near Berkeley, California, please consider attending.  Details below:

Fear of a Black Atheist: How Religion Has Crippled the Black Community
Sunday, January 29th, 6 pm
2040 VLSB at UC Berkeley.

If any readers attend, you can also say hi to me.  I’m the tall Asian guy.  If you live near Sacramento, she is giving the same talk on Thursday.


There is currently a legal defense fundraiser against Richard Carrier.  I talked about Richard Carrier earlier, and how he’s using a lawsuit to silence several people and organizations.  At that time, I mentioned a defense fund for Skepticon, but apparently those funds will only offset Skepticon’s costs.  This new fundraiser is for the other defendants, including the FreeThought Blogs network.  I donated.

Meaning of “theory” in science and pop-science

In science, a theory is “a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed”–according to Wikipedia. This is frequently contrasted with the colloquial meaning of “theory”, which usually refers to something speculative and unconfirmed. It is suggested that in a scientific context, it is more appropriate to refer to a speculative idea as a “hypothesis”.

However, in my experience as a physicist, this is not how the word “theory” is used in practice. Generally, the word “theory” is contrasted with “experiment”, describing the kind of work rather than the quality of the work. Since theories are carefully crafted by experts, it is fair to say that they are more than mere speculation, but that doesn’t mean that every theory has been thoroughly tested and confirmed. Some theories are untested, some theories are in direct competition with other equally viable theories, some theories intentionally model things that do not presently exist, and some theories are just poorly crafted.

So, basically, Wikipedia–and most dictionaries as well–appear to be in conflict with my understanding as a fluent speaker of English physics. That probably means there’s some bad lexicography going on.
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The PBR Theorem explained

The PBR theorem is another theorem of quantum mechanics, which could go alongside Bell’s Theorem and the Kochen-Specker Theorem.  I wrote this explanation in 2011, before the paper was officially published in Nature.  Since then, it’s been recognized as a moderately important theorem, and it has been named after its three authors (Pusey, Barrett, and Rudolph).  But at the time I didn’t really know whether it would become important.

There’s a new paper on arxiv called “The quantum state cannot be interpreted statistically“.  It has a theorem which proves that, given a few basic assumptions, the quantum state (ie the wavefunction) must be real, rather than a merely statistical object.  Nature has an article which mostly just harps on how “seismic” the paper is. 

Nature (correction: the article’s author, not Nature itself) compares its importance to Bell’s Theorem, which is a very important result indeed from 1964.  Bell’s theorem proved that if there were “hidden variables” underneath the quantum state, then entangled particles must be communicating with each other faster than light.  I’ve explained Bell’s theorem in the past.

I felt the news coverage left a lot of unanswered questions.  What do they even mean by the “statistical interpretation” of quantum mechanics?  Roughly how is it proven?  What is the difference between this and Bell’s theorem?  I found the answers in the arxiv print, and will attempt to summarize them.

What does the “statistical interpretation” mean?

Let’s say that we have two ways of flipping a coin.  The first method leads to a 50% chance of heads, and a 50% chance of tails.  The second method rigs it so the coin always comes up heads.  Let’s say that I flipped a coin by one of these two methods, and showed you the result.  If the coin were tails, you could figure out which of the methods I used, but if it were heads, then you would not know which method I used.

Now say that I have two ways of preparing an electron.  And suppose that you measured the vertical spin component of the electron.  If I use the first method, there is a 50% chance the electron is spin up, and 50% chance spin down.  If I use the second method, the electron will always be spin up.  If I prepared the electron by one of these two methods, and you found that the electron is spin up, you would not know which method I used.

But electron spin is a little trickier than coin flips, because you can measure the spin component in any direction.  Suppose you had tried to measure the horizontal spin component, would you always be able to tell which method I used then?  The answer is no.  But perhaps there is yet another way to measure it?

The authors equate the “statistical interpretation” with the following: Given any two different ways to prepare a quantum state, there is a nonzero probability that the result is consistent with either method of preparation.  In other words, no matter what kind of measurement we make, there is a chance that we’ll get an outcome that doesn’t tell us anything.

What’s the difference between this theorem and Bell’s Theorem?

Bell’s theorem requires that you take many measurements and compile statistics of these measurements.  Once you are confident enough in your statistics, you can show that the probabilities are incompatible with the “hidden variable” view of quantum mechanics.

This new theorem requires only one measurement.  One measurement, and you’re done.  (Of course, if you have a noisy experiment, you may need to repeat it to build confidence in your result.)

Of course, the new theorem and Bell’s theorem also have a slightly different set of assumptions, and slightly different conclusions.  But I think the primary difference is that the new theorem requires one measurement, while Bell’s theorem requires compiling statistics.

Roughly how is it proven?

As an example, let’s take the two methods of preparing an electron that I described above.  It turns out that no matter what measurement I make, there is a chance of an outcome that is consistent with either method A or method B.

But we can be tricky.  Let’s duplicate the machine that prepares the electrons, and assume that these machines are independent of each other.  Now there are four methods of preparation:

  1. A and A (ie both machines use method A)
  2. A and B
  3. B and A
  4. B and B

Suppose that there is a chance that the first machine will produce an electron that is consistent with either method A or method B.  There is also a chance that the second machine will produce an electron that is consistent with either method A or method B.  Therefore, there is a chance that both machines produce electrons which are consistent with any of the four methods.

But it turns out that there is a measurement we can make with four possible outcomes. And each outcome is inconsistent with one of the methods.

  • Outcome 1: inconsistent with method 1
  • Outcome 2: inconsistent with method 2
  • Outcome 3: inconsistent with method 3
  • Outcome 4: inconsistent with method 4

What is this special measurement?  It’s not straightforward.  In quantum mechanics, we can measure things like position, momentum, and spin.  But we can also measure things like helicity, which tells you whether the spin and momentum are in the same direction, without telling you what direction that is.  Similarly, we can measure whether the electrons have spin in the same direction or opposite directions.  The measurement described in the paper is sort of like that, but more complicated.

The same theorem can be generalized to any two methods of preparing a quantum state.  Suppose that one method always produces a spin up electron, and the other produces a spin up electron 99% of the time.  All you have to do is have N duplicates of the electron-producing machine (in this case, N=15 suffices), and take a special measurement.  No matter the outcome of this measurement is, it is inconsistent with one of the 2^N possible methods of preparation.

The conclusion is that any two distinct quantum states are not just “probably” different, but always different.  You just need a tricky measurement to show it.

Is this paper as groundbreaking as Nature claims?

I don’t know.

My issues with queer-positive Christianity

In the recent discussion of antitheism, Alex Gabriel brought up his personal experience as a queer atheist:

I keep hearing from believers who take great pains to convince me they don’t hate gay people. Jesus never said anything about it, they tell me, and scripture has been misinterpreted, and the real sinners are homophobes, so for heaven’s sake let that be the end of it. I find that conversation hard, mainly because it never feels like it’s meant to be a conversation. I get the sense I’m expected to nod and sympathise, that my role in the discussion is to validate their feelings, not say what I actually think. It’s as if only part of me gets invited to speak: I’m allowed to oppose religious homophobia as a queer person, but not to critique religion in other forms as a queer atheist. I’m not being asked to participate in a dialogue—just to tell Christians what they want to hear.

As a queer atheist, this is an experience I share. And this is worth ranting about.

A Catholic story

In high school, one of my best friends was gay. I didn’t have the slightest clue about it. I didn’t find out until several years later. He knew it himself, but he didn’t tell people, because my high school was Catholic. Instead, he only told his Catholic parents, and apparently they did not take it well.
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How to actually avoid generalizations

“Don’t make assumptions.” “Criticize the idea, not the person.” “Avoid generalizations.”

These are a few common rules about polite conversation. But they are broken so systematically that it raises the question of whether the rules are any good. One may vocally oppose generalizations, and in the next breath make a sweeping generalization of their own.

It seems that when someone else makes assumptions or generalizations, we hate it. But when we ourselves have the opportunity, we suddenly remember that assumptions and generalizations have some redeeming value after all. And when we next hear someone else make a generalization, we again forget what that value was.

I assert that the value of a generalization is quite simple. People like to state opinions, they like to hear opinions, and they like to use them to inform behavior. They also like to consider opinions and even disagree with them. And if the opinion is stronger by way of generalization, then all the better.

The question for me is not why we like generalizations, but why some generalizations turn out so wrong. What is the source of our aversion? And how can we avoid the kind of generalizations that produce such negative reactions?
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